Swedish supergroup (4)
I believe the answer is:
abba
'swedish supergroup' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for abba that I've seen before include "Bishop" , "Palindromic Swedish pop group who sang ` `Waterloo' '" , "Waterloo singers" , "Eurovision winners" , "Swedish pop band of the 1970s" .)